Method of processing postal items using a separator representing a region of interest (ROI)

1. A method of processing postal items, which method comprises the steps of (a) causing the postal items to advance in series past a camera for the purpose of generating an image of one face of each postal item, which face bears postal address information, (b) filtering the image of a current postal item for the purpose of isolating, in the image, at least one region of interest (ROI) containing the address information, (c) sending the filtered image to an automatic recognition unit for automatically recognizing postal addresses by means of OCR so as to extract the postal address from said filtered image and so as to direct the current postal item to a sorting outlet, and (d) causing a card of the “separator” type to advance past the camera, which card has a face on which a boundary of said region of interest (ROI) is represented graphically, so as to construct a filter mask.

2. A method according to claim 1 , in which at least a portion of an outline of said region of interest (ROI) is represented on the face of the “separator” type card.

3. A method according to claim 2 , in which said portion of the outline of said region of interest (ROI) is represented by a rectangle.

4. A method according to claim 2 , in which said portion of the outline of said region of interest (ROI) is represented by two corners of a rectangle.

5. A method according to claim 1 , in which said filtering step is performed subsequent to said step of causing a “separator” type card to advance past the camera.

6. A method according to claim 1 , further comprising the step of searching the image generated by the camera for the presence of a specific code indicating that said image is the image of a card of the “separator” type on which said region of interest (ROI) is represented.

7. A method according to claim 6 , further comprising, if the presence of said specific code is detected in said image, the step of searching in said image for a rectangular outline that surrounds said specific code and that represents said region of interest (ROI).

8. A method according to claim 6 , in which a bar code is used as the specific code.

9. A method according to claim 6 , in which said searching step includes determining whether said specific code identifies the zone lying within the rectangle as being a zone to be included in or a zone to be excluded from the filter mask.

10. A method according to claim 9 , in which said determining step further includes determining whether said zone has a relative position or an absolute position in the image.

11. A postal sorting machine comprising at least one sorting outlet, a camera for generating an image of one face of a postal item, which face bears postal address information, an automatic recognition unit for automatically recognizing postal addresses by means of OCR, which unit extracts the address information from said image so as to direct the postal item automatically to a sorting outlet corresponding to said postal address, a memory, and an image processing unit which is interposed between the camera and the recognition unit, and which is arranged so that said said image processing unit: detects the presence of a specific code in the current image generated by the camera, which code indicates that said image is the image of a “separator-type” card on which a boundary of at least one region of interest (ROI) is represented graphically; and in response to such detection, said image processing unit constructs, in the memory of the machine, a filter mask corresponding to said region of interest (ROI), applies filtering to an image subsequent to the current image generated by the camera by superposing said filter mask on the subsequent image so as to form a filtered image in which said region of interest is isolated, and sends said filtered image to the recognition unit.

12. A postal sorting machine according to claim 11 , in which the image processing unit is an integral part of said camera.